|
|
Article: Looking under the sheets: inductance: approximating loop inductance can point out the design features that best lower inductance in the power-return path.(THE SIGNAL DOCTOR)
- Article from:
- Printed Circuit Design & Fab
- Article date:
- November 1, 2007
- Author:
CopyrightCOPYRIGHT 2007 UP Media Group, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
INDUCTANCE IS one of the most confusing topics in signal integrity, and, in general, difficult to calculate, there is a special case that is easy to understand and calculate, and surprisingly useful, especially when applied to elements in the power delivery network (PDN).
The loop inductance of an interconnect is the total number of rings of magnetic field lines surrounding the conductor, per amp of current through it. Loop inductance is a measure of the efficiency of the current to create the rings of magnetic field lines. The higher the efficiency for the current loop to produce rings of field lines, the higher the loop inductance.
The reason we care ...